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United States Patent | 6,091,335 |
Breda ,   et al. | July 18, 2000 |
An optical device on board an aircraft for detecting icing conditions including an optical beam emitter to create at least one illuminated external volume of measurement through which there circulates a flow of air charged with water particles; a collector optical system for the collection of at least a part of the light beam back-scattered by the water particles (the external volume of measurement being located on the optical axis of said collector optical system); a photodetector for detecting back-scattered optical beams; a signal processor for processing the signal delivered by the photodetector to compute the severity of the icing conditions; an information provider for providing information on the calculated severity of the icing conditions. Advantageously, the optical means for the differentiation of device includes a differentiation for differentiating between liquid water particles and solid water particles, based on analysis of the polarization.
Inventors: | Breda; Jean-Marc (Vendome, FR); Choisnet; Joel (Naveil, FR); Naim; Monique (Vendome, FR) |
Assignee: | Sextant Avionique (Velizy Villacoublay, FR) |
Appl. No.: | 146539 |
Filed: | September 3, 1998 |
Sep 09, 1997[FR] | 97 11161 |
Current U.S. Class: | 340/580; 244/134F; 250/573; 250/574; 340/581; 340/583; 340/584; 340/600; 340/602 |
Intern'l Class: | G08B 019/02 |
Field of Search: | 340/580,581,583,584,588,589,600,604,602,905 250/573,574,578.1,575 244/134 F 73/170.26,170.17 342/26,22,460 356/381,382,338 |
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J. F. Gayet, et al., "Industrial Measurement Of Microphysical Parameters--Application To Natural And Simulated Icing Clouds", L'Onde Electrique, 72(1992)Jan./Feb., No. 1, pp. 21-25. "Optical Detection Of Ice On A Helicopter Rotor", NTIS Tech Notes, Aug. 1992, pp. 616. |